Drop use of 'oslo' namespace package

The Oslo libraries have moved all of their code out of the 'oslo'
namespace package into per-library packages. The namespace package was
retained during kilo for backwards compatibility, but will be removed by
the liberty-2 milestone. This change removes the use of the namespace
package, replacing it with the new package names. It also adds a local
hacking check to prevent regressions, while disabling style checks in
the "tests" directory, which will be deleted in a subsequent patch.

The patches in the libraries will be put on hold until application
patches have landed, or L2, whichever comes first. At that point, new
versions of the libraries without namespace packages will be released as
a major version update.

Please merge this patch, or an equivalent, before L2 to avoid problems
with those library releases.

Blueprint: remove-namespace-packages
https://blueprints.launchpad.net/oslo-incubator/+spec/remove-namespace-packages

Change-Id: Iad2ae13c771c99861ca9493c6ab10edcfbd8684a

oslo_messaging/_executors/impl_pooledexecutor.py

@@ -18,8 +18,8 @@ import collections
 import threading
 
 from concurrent import futures
-from oslo.config import cfg
+from oslo_config import cfg
-from oslo.utils import excutils
+from oslo_utils import excutils
 
 from oslo_messaging._executors import base
 

oslo_messaging/hacking/checks.py

@@ -0,0 +1,42 @@
+# Copyright (c) 2014 OpenStack Foundation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import re
+
+
+oslo_namespace_imports_dot = re.compile(r"import[\s]+oslo[.][^\s]+")
+oslo_namespace_imports_from_dot = re.compile(r"from[\s]+oslo[.]")
+oslo_namespace_imports_from_root = re.compile(r"from[\s]+oslo[\s]+import[\s]+")
+
+
+def check_oslo_namespace_imports(logical_line):
+    if re.match(oslo_namespace_imports_from_dot, logical_line):
+        msg = ("O323: '%s' must be used instead of '%s'.") % (
+            logical_line.replace('oslo.', 'oslo_'),
+            logical_line)
+        yield(0, msg)
+    elif re.match(oslo_namespace_imports_from_root, logical_line):
+        msg = ("O323: '%s' must be used instead of '%s'.") % (
+            logical_line.replace('from oslo import ', 'import oslo_'),
+            logical_line)
+        yield(0, msg)
+    elif re.match(oslo_namespace_imports_dot, logical_line):
+        msg = ("O323: '%s' must be used instead of '%s'.") % (
+            logical_line.replace('import', 'from').replace('.', ' import '),
+            logical_line)
+        yield(0, msg)
+
+
+def factory(register):
+    register(check_oslo_namespace_imports)

tools/simulator.py

@@ -25,10 +25,10 @@ import logging
 import sys
 import time
 
-from oslo.config import cfg
+from oslo_config import cfg
-from oslo import messaging
+import oslo_messaging as messaging
-from oslo.messaging import notify
+from oslo_messaging import notify  # noqa
-from oslo.messaging import rpc
+from oslo_messaging import rpc  # noqa
 
 LOG = logging.getLogger()
 

tox.ini

@@ -42,13 +42,14 @@ commands = {toxinidir}/setup-test-env-zmq.sh python setup.py testr --slowest --t
 [flake8]
 show-source = True
 ignore = H237,H402,H405,H904
-exclude = .tox,dist,doc,*.egg,build,__init__.py
+exclude = .tox,dist,doc,*.egg,build,__init__.py,tests
 
 [hacking]
 import_exceptions =
   oslo_messaging.openstack.common._i18n
   oslo_messaging._i18n
   six.moves
+local-check-factory = oslo_messaging.hacking.checks.factory
 
 [testenv:pip-missing-reqs]
 # do not install test-requirements as that will pollute the virtualenv for